This work addresses the design of optimal input shaper and its application to the motion control of a robotic workcell. An optimal shaper is proposed to tradeoff performance and robustness according to assembly specifications of the workcell. The optimal shaper, along with standard shaper designs such as Zero Vibration, zero vibration and derivative, and extra insensitive are applied to conduct cycle time testing on a two-axis adept technology robotic workcell. The performance for various unknown loading conditions is observed. It is shown that the optimal shaper produces the best overall results.